A1.79 m long uniform rod with a mass of 2.03 kg is allowed to rotate. by
pushing perpendicularly on the edge of the rod, a student produces an
angular acceleration of 12.9 rad/s2. what is the minimum force the
student could be providing if (a) the rod is rotating around its center.
what is the minimum force the student could be providing if (b) the rod
is rotating around the opposite end?

(a) 7.81 N

(b) 15.6 N

Explanation:

For a rod rotating around its center, I = 1/12 mL².

For a rod rotating around its end, I = 1/3 mL².

(a) Sum of the torques on the rod:

∑τ = Iα

F L/2 = (1/12 mL²) α

F = 1/6 m L α

F = 1/6 (2.03 kg) (1.79 m) (12.9 rad/s²)

F = 7.81 N

(b) Sum of the torques on the rod:

∑τ = Iα

FL = (1/3 mL²) α

F = 1/3 m L α

F = 1/3 (2.03 kg) (1.79 m) (12.9 rad/s²)

F = 15.6 N

what experimental evidence led scientists to change from the previous model to this one?

a few of the positive particles aimed at a gold foil seemed to bounce back.

the colors of light emitted from heated atoms had very specific energies.

experiments with water vapor showed that elements combine in specific proportions.

cathode rays were bent in the same way whenever a magnet was brought near them.

answer( sicar );